In recent years, applying equipment of mixing fluids in a micro flow path manufactured by micro fabrication techniques, so-called a microreactor, to biochemistry, medical field or the field of chemical reactions has been performed vigorously. One of chemical reactions, a photoreaction of proceeding a reaction by utilizing light energy (a photochemical reaction) has been known.
As a feature of the photoreaction in the microreactor, it has been known that the efficiency of the photoreaction is improved extremely since light from a light source easily reaches the lowest portion of a fluid due to reduction in the size of a reaction space to enable uniform light irradiation.
Accordingly, it is expected that the reaction in which the efficiency of the photoreaction is lowered by a usual batch method can also be performed easily at a high efficiency by the microreactor.
For the microreactor proceeding the photoreaction, various developments and studies have been made so far.
At first, a microreactor having a reaction part formed of a tubular light transmitting flow path and a light source part having alight source causing photoreactions has been known (for example, refer to Patent Document 1).
Secondly, it has been known a microreactor for photoreactions in which a channel is formed on a planar substrate made of SUS316 as a stainless steel or made of PTFE (polytetrafluoroethylene), and a flow path is formed by a cover made of quartz glass (for example, refer to Non-Patent Document 1).
Thirdly, with an aim of increasing the sensitivity of detection values, a method of reflecting light for multiple times by devising the structure of flow paths has been known (for example, refer to Patent Documents 2, 3).
Fourthly, with an aim of improving the accuracy and the separation in the synthesis of DNA microarrays, there has been known a method of using a material having a diffractive index identical with that of a fluid, or providing an anti-reflection film (for example, refer to Patent Document 4), and a method of using an anti-reflection film or providing a light absorption layer coated with a spray coating material opposing to an irradiation/detection part with an aim of increasing the sensitivity of detection values (for example, refer to Patent Document 5).